Facile fabrication of the Zn0.5Cd0.5S/ZnIn2S4 S-scheme heterojunction for efficient photocatalytic hydrogen production and tetracycline degradation

Improving the photo-induced charge separation efficiency is an important route for enhancing the photocatalytic performance of ZnIn2S4. In this research, an S-scheme heterojunction comprising ZnIn2S4 and Zn0.5Cd0.5S was successfully formed using a facile oil-bath method followed by a subsequent hydrothermal process. The Zn0.5Cd0.5S/ZnIn2S4 composites displayed enhanced photocatalytic activities during H2 generation and tetracycline (TC) degradation. Among the composite materials, the Zn0.5Cd0.5S/ZnIn2S4-20 wt% hybrid nanomaterial demonstrates a superior visible-light hydrogen evolution rate of 780 μmol g−1·h−1 and a TC degradation activity of 98% with excellent reusability, which are nearly 5.77 and 5.76 times greater than those of ZnIn2S4, respectively. The significantly enhanced photocatalytic performance of the Zn0.5Cd0.5S/ZnIn2S4 hybrids can be ascribed to the well-designed S-scheme heterojunction. This design accelerates interfacial charge separation, increases the specific surface area, and broadens the visible light response range. This research paves the way for developing ZnIn2S4-based dual-function systems with greatly improved charge separation, leading to high-efficiency photocatalytic activity.